Storage
Perfect storage conditions are essential for the protection of olive oil from its worse enemies: light, heat and air oxygen, that can cause irreparable damage to the chemical and sensory characteristics of even the finest extra virgin oil.
 

Yesterday
Traditionally ad hoc baked-clay vases were used for storage. Huge such containers were found in palaces of the ancient East. In the Mycenean and Cretan palaces of Greece, warehouses with hundreds of great vases were discovered which could hold hundreds of kilograms of oil.
Throughout all the Mediterranean area after the Middle Ages, these containers were supplied to the oil-producing areas by specialized potters in localities that became famous for their production.
In more recent centuries these vessels were replaced by stone reservoirs, placed underground and protected from light and sudden changes in temperature. Later, the stone finish was replaced by glazed ceramic tiles that allowed greater cleanliness and better conservation. 
Jar - Southern Italy
The picture shows a jar for oil storage. Its neck carries an identification mark, common usage in the storage of oil at that time.

Today
Stainless steel tanks are the modern standard for the storage of large quantities of olive oil; they afford protection from light and easily sanitized, thus offering highest guarantee of correct conservation.
Proper conservation of olive oil in the home is likewise important: it must follow the criteria of safeguard and protection that the characteristics of the product require.
If correctly stored, olive oil can be consumed even mere than two years after it was produced because it contains antioxidants that protect it from becoming rancid. The containers must be of dark glass or tinplate, to protect the contents from light, and must be stored in a dark, cool place. 
Steel tanks
The picture shows tanks installed inside an air conditioned building used exclusively for storage of extra virgin olive oil.